Lecture: Refraction and Retinoscopy in Children – Refractive Error and Management

In this lecture, Kim McQuaid discusses the following topics:

Ways to gain a child’s trust and cooperation for an eye exam

Conditions that can be revealed by first impressions and binocular assessments

Why retinoscopy and cycloplegia are vital for determining refractive error

Some methods for managing pediatric refractive error

Lecturer: Kimberly McQuaid, Technician

Transcript

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DR MCQUAID: So the objectives of my talk today are hopefully that when we’re done here you will, first of all, be able to describe some ways in which to gain a child’s trust, so that you can actually make a vision assessment, and perform some retinoscopy or refraction. I’d like you to be able to name a few conditions which can be revealed by your first impression of seeing the child, and some very simple binocular assessments. You should be able to explain when we’re done here why retinoscopy is such an important, vital skill to have when it comes to dealing with children. And then you should also be able to mention a couple of ways to manage pediatric refractive error. So now the thing is — is I’m not going to stand up here and teach you how to did retinoscopy or how to do refraction on a child or anybody else. What I’m gonna do here is just give you some insight and some quick non-confrontational-type tests, and that sort of thing. I’m going to assume that many, if not most of you, at least know how to do some retinoscopy. And if you don’t know how to do retinoscopy, I’m hoping that you’re gonna leave with an understanding of why this is a skill that you should really learn and practice. So I had set this up with some questions to start with. I guess our clickers are not working, so I’ll have you just kind of answer these in your head, or write them down, what your impression is, to begin with. So would this statement be true or false? When examining a child, one should proceed slowly, since children cannot keep up very easily? Second question. A test called Bruckner’s test — true or false? Bruckner’s test can provide information about refractive error and the presence of strabismus? True or false, cycloplegic eye drops should be instilled prior to retinoscopy of young children? And this one is multiple choice. When doing a monocular assessment of a child’s vision, one should… Number one, allow the child to hold the occluder his or herself. Number two, allow the child to cover his own eye with his own hand. Number three, use an adhesive eye patch. Or number four, allow the child to keep both eyes uncovered. So only one of those answers is correct. So as an introduction, first of all, uncorrected refractive errors in children of all errors can really lead to a lot of problems with their development, their educational opportunities, their quality of life, and their eventual career opportunities, as they grow older. But I think that we all know, or at least can imagine, how difficult and challenging it is to determine whether a child needs glasses, especially those children that aren’t even able to speak yet. So it turns out that creative and accurate and fast retinoscopy skills are invaluable in discovering refractive error in children that needs correction. And I do mention that that is specifically refractive error that needs correction. Because not all refractive errors in children actually needs to be corrected. And also, when it comes right down to it, if you’re gonna prescribe a pair of glasses for a child, you want to encourage the child and give some positive reinforcement, in order to make sure that the child actually wears the glasses, once you’ve given them the prescription. So just a brief history of the refractive development of children. Typically, from birth to the age of 12 months, children are very often up to about 2 diopters of hyperopia. From about 3 months to that 12-month period, there is a period of rapid emmetropization. That is, the hyperopia starts to disappear. And it happens usually pretty quickly in the latter half of the first year of life. It’s very common for children under the age of about 3 to have even up to about 2 diopters of astigmatism. And the astigmatism itself tends to gradually decline and stabilize by the time they’re about 4 or 5 years old. And once the child enters school, once they’re old enough to begin school, there tends to be a more gradual movement of the refractive error towards emmetropia, and then as they reach early teenage years, they tend to go a little myopic. So your first impressions, when you’ve got a kid coming into your room — the first thing I would say is lose the white coat. Don’t look like a doctor. That’s going to give a little more comfort to the child. And if you know you’re going to be seeing kids that day, or maybe you can even just keep in a locker or a closet somewhere — just some colorful, child-friendly clothing. Things that they can look at and play with. You know, fun earrings or bow ties or things like that. You know, introduce yourself by your first name only. You don’t to be Dr. So and so today. You can just be called by your first name. And make eye contact with the child. And also, always explain things. Like what you’re gonna be doing to them, or what’s gonna be happening. Explain those things in positive terms. And it helps to be a little silly. A little sillier than you would be in your own life. People with their own children — this ends up being very easy. People without their own children, it can be a little more of a challenge. But be a little funny. It’s okay. And when a child walks into my room for the first time, I tend to focus all my attention onto the child, while kind of just giving the parent themself my peripheral attention. I want the child to know that the parents and I are friendly, but I also want the child to know that that is the person that is the focus of my attention. So when I have a child that comes into my room with a parent, I tend to focus my attention on the child rather than the parent. You know, I do smile and acknowledge the parent and speak to them in a friendly way, because the child will find that if the parent trusts me, then the child himself can trust me as well. Okay. So there are some things that we can discover the moment the child walks in the room. There are some first impressions that can really help us a lot with our assessment. Looking at the child as they walk into the room, there are things that you can see immediately. Do they have an obvious lid abnormality, for example? Do they have a ptosis or a giant chalazion on their eyelid? And why does that matter when we’re talking about refractive error? Because those types of lid abnormalities can actually lead to astigmatism. Noticing whether the child has an obvious strabismus is also of a great help. Because if the child walks in, and there’s one eye stuck in at their nose, one eye that is esotropic and remains that way for the duration of your encounter, you can assume that that esotropic eye is not seeing very well. However, if they come in, and they’re obviously alternating their fixation, then you can make the assumption that they actually do have pretty decent vision in both eyes. And I do always take a moment to ask the parent: How do you think the child sees? Because parents, they do know best. So if you ask the parent — do you think your child sees? Even if it’s a little baby, do you think your baby sees? Or do you think the child sees? Does the child see the airplanes in the sky or the little particles on the ground that they try to pick up? Because you can also ask about their school performance. Are they sitting very close to the front of the classroom? Are they able to keep up when they’re sitting behind? And you can ask them about the child’s visual behavior, as compared to the other children in the family. So as far as the examination itself, of course, an infant is gonna be sitting on the parent’s lap. Toddlers and young children, preschool children, tend to be quite shy, so it’s usually preferable to have them sitting on the parent’s lap as well, or at least have the parent very nearby. And as the child enters its school age, sometimes they start wanting to show off a little bit. They’re a little proud to be able to demonstrate to you what they are capable of. So at that point, sometimes they can be encouraged to sit alone in the exam chair. Of course, with the parent still in the room. So one quick test that we can do, that will give us a binocular assessment — these first few tests that I’m gonna talk about are kind of non-confrontational. So they’re meant to make a quick assessment of the overall visual behavior, without having to put a patch on one eye or cover one eye or not. So this optokinetic drum — they make them with just the stripes, and then they also make a pediatric version with some pictures on there. Optokinetic nystagmus is an innate reflex that we all have, that occurs when one tries to keep a moving object stationary on their fovea. And this reflex is innate, and it’s actually very crudely developed, basically, at birth. So in newborns. And even more so — by the time a baby is five or six months old, this reflex is pretty helpful for us. And what’s happening is, as you’re spinning this drum — this drum rotates — as you’re spinning this drum slowly, a person has a tendency, a baby or otherwise, a person has a tendency to choose one stripe and follow it, until it disappears. So they have a slow eye movement, as the stripe goes around, and then they have a faster eye movement, to pick up a new stripe. So what we’re doing here is inducing a nystagmus. And that indicates — if it occurs — it indicates that the macula is getting an image of these stripes, and that there is at least a fairly normal visual pathway. So another binocular assessment that we can do — it’s called Bruckner’s test. And this uses a direct ophthalmoscope. And this is often one of the very first things I’ll do, when a kid comes into my room. Flip the lights off, flip the direct ophthalmoscope on, and just kind of shine from about a half a meter to a meter distance, shine a circle of light so that it strikes both eyes at the same time. And what you’re gonna see is the red reflex coming back at you. When you see these crescents, these light-colored crescents here in the upper portion of the pupil, that’s a pretty hyperopic reflex that you’re seeing. When you see the crescents in the lower portion of the pupil, that’s more of a myopic reflection you’re seeing. And what you’re really expecting or hoping for is some kind of equal red reflexes. Now, do keep in mind, as I said, that so many very young children are hyperopic to begin with. So seeing the hyperopic crescents is very common in young children. Turns out that seeing the myopic crescents is gonna actually give you more information, be more telling as to what their refractive error is gonna be down the road. The pupil does not have to be dilated for this. Nope. You flip the room lights off and just put that right on there. Don’t need to dilate them. Don’t need to touch them. So another neat thing about Bruckner’s test is that if you see that one reflex is red and the other one is lighter than the other, or white, oftentimes the lighter — the eye with the lighter-colored reflex is strabismic. But don’t jump to any conclusions, because there are many reasons, of course, why a leukocoria is more than just the strabismus. You know, a leukocoria can be a bad thing. Okay. So another neat test that you can do on kids right away, when they get in the room — again, another thing — you don’t have to touch the child. You don’t have to get a whole lot of background information. But you can do a binocular stereo test. So there are these types of stereo tests, which require no special glasses, and then of course there’s the famous fly test down there, where you do have to put on the polarized glasses. These tests do not need special glasses. But the cool thing is that kids love this test. They love to do these stereo tests. And if they have good stereopsis, that’s a pretty good indication that they have at least equal vision in both eyes, and usually equal and good vision in both eyes. And then another thing you can do, before you have to put any drops in or do anything else to the child, is a quick cover-uncover test, or a cover-cross-cover test. And these cover tests, they’re gonna give you a good idea as to whether they have a phoria or a tropia, or the possibility of an amblyopia. So in order to assess a child’s vision on a monocular basis, it’s very hard on the very young to get an accurate visual acuity out of each eye individually. So rather than trying to assign a number — you know, a value to their visual acuity in each eye — focus your attention more on the difference between the two eyes. The difference or the similarities between the two eyes. So the first thing you can do is cover one eye. And observe the child. Do they fixate with the uncovered eye? Do they follow objects, moving objects, with the uncovered eye? Or do they fuss and really struggle when you put that patch on? And then you want to cover the other eye. And make the same assessment. Does the second eye fixate? Does it follow? Or does the child fuss and complain when you’ve covered it? Because one of the telling things is: If you cover, if a child has amblyopia, and you cover their good eye, they tend to get quite agitated. And then one thing that I will say a few times today is, when you are checking vision on a monocular — when you are checking monocular vision in children, really, whenever possible, if at all possible, use an adhesive patch to do so. And the reason I say that is because kids want to be able to see, and they will do anything in order to see. So that means they’ll peek around or above or through your fingers or anything, in order to be able to see. Now, having said that, kids that are about one year of age absolutely hate having that sticky patch on their eye. So very often — you do need to be adaptable and you need to be creative. Young kids, you can use your thumb, but do keep in mind the limitations of not using an adhesive patch. So these methods I’m gonna talk about here — this will allow you to assign a value, you know, to their visual acuity. But keep in mind that each one of these methods does have its limitations. These Teller acuity cards work on the premise of preferential viewing. There’s a gradient of stripes on one side. There’s a hole right there in the middle, that the examiner looks through. When you hold the card up to the baby, the baby is going to be drawn to the grating, if they can see it. So I do find that these Teller cards work very well, typically, for kids that are two and a half and three years of age and younger. They do give us a value for visual acuity in terms of Snellen number, but they’re not an exact match. Older children, you know, children who are reaching preschool age and learning — and are able to speak and interact with you a little bit, Allen pictures and HOTV, these types of matching games, work really well. But when it comes to proper visual assessments, visual acuity assessments, you really want to get the child doing the Snellen — the adult charts — as soon as possible. One thing to keep in mind is that you do need to work pretty fast with these kids, because their attention span is about as long as a fly. So if you can get that patch on them quickly and have them even just read a couple of lines, a couple of letters on each line, before you move on to the next one — you don’t have to sit there and wait for them to get all five letters on every line. You know, a couple, before you move down to the next one, is adequate. So the title of this slide — determining refractive error — retinoscopy. Learn it. And that’s really all I have to say. If you’re going to be examining children, this is a skill that you really need to have and to practice. Okay. Some of the reasons for this. Number one: Why is it so important? Because if a child is too young to even speak with you or give you any kind of subjective input, your retinoscopy is going to be the basis of the prescription for glasses that we give them. So you don’t want to be too wrong with this. The other thing — retinoscopy, it reveals more than just the patient’s refractive error. You can typically easily see if there are cataracts or some other type of media opacity, if something is blocking your reflex. So the first reason that we should learn this is because sometimes our retinoscopy is the only basis on which we have to give a child a prescription for glasses. So what we get is what they get. There are several different methods of doing retinoscopy, and I’m not going to go into very much detail on any of these, other than to say that there are a few different methods for it. The method of retinoscopy that I strongly recommend you work with is just static retinoscopy, done under cycloplegia. So as with all aspects of the pediatric eye exam, speed is of the essence. So practice your retinoscopy skills. Get good at them. Do it every chance you get on every person you get a chance to do it. Because more practice and experience is what’s gonna make you fast and accurate. Obviously you’re not gonna be able to use a phoropter on a young child, so you’ll need to get proficient with the use of trial lenses, loose lenses, skiascopy racks, and trial frames.And the best way for you to determine with retinoscopy a kid’s refractive error is to cycloplege them. And I say this because, as you’re scoping them, if they’re not cyclopleged, what you’re seeing is gonna change by the moment. In our practice, for children under the age of 1 year, we use a drop called cyclomydril, which is a 0.2% cyclopentolate with 1% phenylephrine combination. Put the drop in two or three times, at 5-minute intervals. Once they’re a year old, from age one year to about the age of 12 or 13 years, we use 1% cyclopentolate, instilled, again, a couple of times with 5-minute intervals. And what you’ll find is — the reason I’m recommending cyclopentolate is because tropicamide as a cycloplegic is just not strong enough for kids. They can overcome it. Okay. And once you’ve got those drops in, you’ve got to give them a little bit of time to work. So the full cycloplegia is not gonna occur for 35 to 45 minutes. So give them time. Don’t rush that period of time you need to wait. And it’s very important to tell the parent as well that it could take 6 to 24 hours for the child to totally recover from the cycloplegia as well. So not to panic if even the next morning, the child wakes up with enlarged pupils. As with any medication we use in our clinics, there’s always an outside chance that the child could have an allergic reaction or an idiosyncratic reaction to the eye drops. So it’s helpful to be aware of what those eye drop reactions might be. That they’re very rare, and to be able to address those as they come up. And also, if you’re the one that’s assessing the child from beginning to end, you’re the one that’s going to be doing the retinoscopy, it’s kind of helpful if you can have your nurse or your assistant or your technician be the bad guy and put the eye drops in. Because the cycloplegic drops, they sting. The little kids, they don’t like you having to pry open their eyes to put the drops in, and you need to keep their cooperation and their trust. So have somebody else do that, so that the patient will keep their trust in you. So as far as the subjective refraction on kids, for obvious reasons, you cannot subjectively refract a child who cannot speak or give you their cooperation. Being able to elicit meaningful responses from the kid is totally, totally dependent on the child themselves. And for some kids, that might be 5 or 6 years old. For others, they might be 11 or 12 years old before you can get meaningful responses. And with any kids, in any type of examination on kids, you want to get as much information as you can in as short a time as possible. So when you’re doing retinoscopy on them, or when you’re trying to refract them, you can use bigger, larger lens changes than you might, say, for a subjective refraction on a cooperative adult. So that is — you don’t have to get it exactly right. If you can get that refraction or that retinoscopy within half a diopter or 3/4 of a diopter, that’s gonna be close enough, and you’re gonna appreciate that you’ve been able to get through that so much faster. And depending on what you’re coming up with, with your spherical corrections, you may even want to forego pursuing the cylindrical correction, if there is one. Maybe instead go with the spherical equivalent. Yeah. Instead of delving into getting an exact cylindrical correction, you may want to instead just get an idea of what the cylinder correction would be, and instead give them a spherical equivalent. So kids, if you are getting subjective responses, kids are very easily led with yes or no questions, so I would try to avoid asking them questions that require yes or no. Because 95% of the time, they’re gonna say “yes”. They want to please you. So their answer is almost always gonna be “yes”. And when you’re giving them choices, don’t give them 10 choices. Don’t give them 5 choices. Don’t give them 3 choices. Just give them 2 choices. Number 1 or 2. A or B. And if you are getting subjective responses that you feel are reasonable, if the child is asking for more minus power to be added to their prescription, you need to have them prove that they need that minus power by reading an additional line on the eye chart. Because of their accommodative ability, of course, a kid could actually focus through an excessive 2, 3, 4, even 5 diopters of too much minus. A kid could focus through that. So you don’t want to give them that minus, unless it actually improves the vision. As far as managing a kid, once you’ve decided that they need some glasses or need a prescription, it’s important first of all to make sure that the parents — educate the parents, and your pediatricians, in your area, pediatric providers — educate them about the importance of early vision screening, to begin with. Getting some kind of a cursory examination by the time they’re six months old — that’s not even two early. Six months old to one year old, somebody should be having a quick look at their vision. And then it kind of just depends the extent to which the child is at risk — is gonna kind of have you evaluate the schedule. How frequently should the kid be seen. If they can wait until they’re in preschool to be seen again. And of course, if you find a child that does have an obvious problem, an obvious amblyopia or other eye pathology, you really want to emphasize the importance to the parents of having them keep those follow-up appointments. Make sure they understand how important it is that they come back for follow-up. And then keep in mind what I said earlier. It’s that the parent really does know best what’s going on with their child. So if they do have a concern that they bring up to you, take it seriously and listen closely. Don’t think just because you’re the doctor you know better. It’s actually the parent who knows best. So if something is going on, they’re gonna notice. And as far as getting the kid to wear the prescription that you’ve written for them, it’s helpful to allow the child to choose their own glasses frames. For little, little kids, you want to especially make sure that the frames are comfortable on their face and their head. Sometimes kids don’t want to wear their glasses just because they hurt them behind their ears or on their nose. And then for children who are a little more mature or a little bit older, contact lenses can be an option. So, in conclusion, when it comes to determining the refractive error in a child, knowing how to do retinoscopy fast is crucial. I would recommend being creative and adaptive in your approach to working with kids. There are a lot of things that you can do to assess the child and their vision without even touching the child. The moment they first come in the room, there’s a lot that you can do without even laying a hand on them. Use an adhesive eye patch when at all possible, when you’re testing vision on a monocular basis. Use cycloplegia. Use cycloplegic eye drops, because otherwise your refractions, your retinoscopies, are gonna be all over the place. And educating the parents as well as the other pediatric care providers in your community, as to the importance of follow-up appointments and vision assessments — this is gonna be really important for you to be able to follow up on these kids and catch problems early, before they get serious. So what this says up here — it says most children have no idea how they are supposed to see. So when words look like this, they assume everyone sees the same way they do. And imagine how frustrating that would be.